Known in the art are electric machines with the stator core and winding directly cooled by a fluid coolant (cf. V.V. Titov and other. "Turbogeneratory. Raschet i Konstruktsia." M., "Energia," 1967, p. 200), wherein the fluid coolant circulates within the ducts made formed in individual elements such as tubes, segments, etc., located inside the radial or axial ducts of the stator core and winding. The structure of the cooling units in these machines is rather complicated and, as a result of many junctions employed, is unreliable. A supercharger (a pump, a compressor, etc.) is an obligatory element in the cooling medium circulation system.
Also known in the art is an electric machine (cf. U.S. Pat. No. 3,530,320), comprising a rotor, a stator separated from the former by a sealed jacket which forms closed chambers of the stator winding end-connectors, communicating with each other through ducts of a complicated configuration, having, in turn, radial and axial sections, and also through an external pipeline intended for a cooling medium to circulate within the stator. The external pipeline incorporates a cooler and a supercharger (a pump or a fan). To effect forced circulation of the cooling medium, the supercharger consumes a certain amount of electric energy, thereby reducing the electric machine efficiency. In addition, the employment of devices with movable parts and units considerably reduces the operating reliability of the electric machine.